International Crops Research Institute for the Semi-Arid Tropics
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Genome-wide association mapping of seed oligosaccharides in chickpea
Get PDFChickpea (Cicer arietinum L.) is one of the major pulse crops, rich in protein, and widely consumed all over the world. Most legumes, including chickpeas, possess noticeable amounts of raffinose family oligosaccharides (RFOs) in their seeds. RFOs are seed oligosaccharides abundant in nature, which are non-digestible by humans and animals and cause flatulence and severe abdominal discomforts. So, this study aims to identify genetic factors associated with seed oligosaccharides in chickpea using the mini-core panel. We have quantified the RFOs (raffinose and stachyose), ciceritol, and sucrose contents in chickpea using high-
performance liquid chromatography. A wide range of variations for the seed oligosaccharides was observed between the accessions: 0.16 to 15.13 mg g-1 raffinose, 2.77 to 59.43 mg g-1 stachyose, 4.36 to 90.65 mg g-1 ciceritol, and 3.57 to 54.12 mg g-1 for sucrose. Kabuli types showed desirable sugar profiles with high sucrose, whereas desi types had high concentrations RFOs. In total, 48 single nucleotide polymorphisms (SNPs) were identified for all the targeted sugar types, and nine genes (Ca_06204, Ca_04353, and Ca_20828: Phosphatidylinositol N-acetylglucosaminyltransferase; Ca_17399 and Ca_22050: Remorin proteins; Ca_11152: Protein-serine/threonine phosphatase; Ca_10185, Ca_14209, and Ca_27229: UDP-glucose dehydrogenase) were identified as potential candidate
genes for sugar metabolism and transport in chickpea. The accessions with low RFOs and high sucrose contents may be utilized in breeding specialty chickpeas. The identified candidate genes could be exploited in marker-assisted breeding, genomic selection, and genetic engineering to improve the sugar profiles in legumes and other crop species
Improved pea reference genome and pan-genome highlight genomic features and evolutionary characteristics
Get PDFComplete and accurate reference genomes and annotations provide fundamental resources for functional genomics and crop breeding. Here we report a de novo assembly and annotation of a pea cultivar ZW6 with contig N50 of 8.98 Mb, which features a 243-fold increase in contig length and evident improvements in the continuity and quality of sequence in complex repeat regions compared with the existing one. Genome diversity of 118 cultivated and wild pea demonstrated that Pisum abyssinicum is a separate species different from P. fulvum and P. sativum within Pisum. Quantitative trait locus analyses uncovered two
known Mendel’s genes related to stem length (Le/le) and seed shape (R/r) as well as some candidate genes for pod form studied by Mendel. A pan-genome of 116 pea accessions was constructed, and pan-genes preferred in P. abyssinicum and P. fulvum showed distinct functional enrichment, indicating the potential value of them as pea breeding resources in the future
Reaping the Potential of Wild Cajanus Species through Pre-Breeding for Improving Resistance to Pod Borer, Helicoverpa armigera, in Cultivated Pigeonpea (Cajanus cajan (L.) Millsp.)
Get PDFPod borer (Helicoverpa armigera) causes the highest yield losses in pigeonpea, followed by pod fly (Melanagromyza obtusa). High levels of resistance to pod borer are not available in the cultivated genepool. Several accessions of wild Cajanus species with strong resistance, and different resistance mechanisms (antixenosis and antibiosis) to pod borer have been identified. These accessions can be utilized to improve the pod borer resistance of cultivated pigeonpea. Using pod borer resistant Cajanus scarabaeoides and Cajanus acutifolius as pollen donors and popular pigeonpea varieties as recipients, pre-breeding populations were developed following simple- and complex-cross approaches. Preliminary evaluation of four backcross populations consisting of >2300 introgression lines (ILs) under un-sprayed field conditions resulted in identifying 156 ILs with low visual damage
rating scores (5.0–6.0) and low pod borer damage (<50%). Precise re-screening of these ILs over different locations and years resulted in the identification of 21 ILs having improved resistance to pod borer. Because these ILs were derived from wild Cajanus species, they may contain different alleles for different resistance components to pod borer. Hence, these ILs are ready-to-use novel and diverse sources of pod borer resistance that can be utilized for improving the pod borer resistance of cultivated pigeonpea
Association of Grain Iron and Zinc Content With Other Nutrients in Pearl Millet Germplasm, Breeding Lines, and Hybrids
Get PDFMicronutrient deficiency is most prevalent in developing regions of the world, including
Africa and Southeast Asia where pearl millet (Pennisetum glaucum L.) is a major
crop. Increasing essential minerals in pearl millet through biofortification could reduce
malnutrition caused by deficiency. This study evaluated the extent of variability of
micronutrients (Fe, Zn, Mn, and Na) and macronutrients (P, K, Ca, and Mg) and their
relationship with Fe and Zn content in 14 trials involving pearl millet hybrids, inbreds, and
germplasm. Significant genetic variability ofmacronutrients andmicronutrients was found
within and across the trials (Ca: 4.2–40.0mg 100 g−1, Fe: 24–145mg kg−1, Zn: 22–
96mg kg−1, and Na: 3.0–63mg kg−1). Parental lines showed significantly larger variation
for nutrients than hybrids, indicating their potential for use in hybrid parent improvement
through recurrent selection. Fe and Zn contents were positively correlated and highly
significant (r=0.58–0.81; p<0.01). Fe and Zn were positively and significantly correlated
with Ca (r = 0.26–0.61; p < 0.05) and Mn (r = 0.24–0.50; p < 0.05). The findings indicate
that joint selection for Fe, Zn, and Ca will be effective. Substantial genetic variation
and high heritability (>0.60) for multiple grain minerals provide good selection accuracy
prospects for genetic enhancement. A highly positive significant correlation between Fe
and Zn and the nonsignificant correlation of grain macronutrients and micronutrients with
Fe and Zn suggest that there is scope to achieve higher levels of Fe/Zn simultaneously in
current pearl millet biofortification efforts without affecting other grain nutrients. Results
suggest major prospects for improving multiple nutrients in pearl millet
Farm Parent and Youth Aspirations on the Generational Succession of Farming: Evidence From South India
Get PDFAgriculture remains vital in ensuring the food security of developing economies like India,
yet increasing rural-urban migration, an aging farm population, and waning interest of
rural youth in agriculture are emerging concerns. This paper focuses on the aspirations of
farm parents and their children in agriculture, the challenges they confront, and potential
solutions.We draw on qualitative data fromtwo rural sites in Southern India, different from
each other in their agro-ecological and social contexts, to point to the material, social,
relational, and structural factors shaping aspirations. First, agrarian distress, resulting
from climate variability and market uncertainty, affects farm households’ socioeconomic
status, resulting in farmers’ aspiration failure in agriculture. Farm parents then focus on
educating their children, aspiring for secure non-farm jobs for their sons, and finding
suitable marriage partners, also in non-farm employment, for their daughters. While this
steer from parents discourages youth from aspiring to careers in agriculture, in reality,
there is a wide gap in the achievement of aspirations, and a majority of youth, especially
young women, do end up working on their family farms. For the future development of
agriculture and sustainable food systems, it is essential to protect young farmers from
aspiration failures and innovate through appropriate policies
Responses of N2O emissions to straw addition under different tillage soils: A 15N labelling study
No full textNitrous oxide (N2O) emissions contribute to global climate change and are regulated by the intensities of N
mineralization, nitrification and denitrification processes. These processes depend on soil management, e.g.,
tillage and straw addition. Microbial mechanisms underlying the effects of straw addition on N2O emissions were
investigated by 56-day incubation of soil from a long-term (27-year) no-tillage (NoTill) and conventional tillage
(ConvTill) field experiment. The abundance of N functional genes (amoA, amoB, nirK, nirS and nosZ) in no-tillage
and conventional tillage soils was analysed based on straw addition. The application of 15N-labelled straw
allowed us to trace N2O sources. Conventional tillage with 15N-labelled straw (ConvTill+Straw) reduced N2O
emissions derived from soil by 42 %, whereas no-tillage with 15N-labelled straw (NoTill+Straw) reduced N2O
emissions by only 8 % compared with soil without straw addition. The N2O emissions derived from straw were
higher under NoTill+Straw than under ConvTill+Straw, whereas they accounted for only ~4 % of the total N2O
emissions under both conditions. The nirK and nirS gene abundances were higher than those in soil without straw
addition. Compared to that under ConvTill, the nosZ gene abundance was higher and the N2O emissions were 40
% lower under ConvTill+Straw, indicating its strong capacity to reduce N2O to N2. Pathway analysis showed that
gene (amoA and nirK) abundance combined with soil properties (particulate organic matter nitrogen (POMN) and
NO
Determinants of Income Diversification among Dairy Farm Households in Tamil Nadu
Get PDFDairy farming is the subsidiary occupation for millions of farmers in India. Due to risks and uncertainties in rainfed areas, crop production alone was not much remunerative. Diversifying dairy with the crop and allied activities would generate better income, nutritional security, and regular employment to the farming community and ensure risk reduction. This study investigates the extent and determinants of income diversification among dairy farm households in Tamil Nadu using the Simpson Index of Diversity (SID) and the Tobit regression model. Primary data were collected from dairy farm households during the year 2021-22. The results show that two-thirds of the total household income was shared by on-farm income and the remaining one-third by off-farm and non-farm activities to the total household income. Simpson Index of Diversity (0.38) indicated that the households were diversified with milch animals, but the degree of the diversification was low since high degree of diversification requires more labour and high cost. Further, education, family size, landholding size, herd size, proximity to agricultural or allied industry, access to credit, and membership in farmer producer organizations were the important determinants of income diversification. This study indicates that farm households should adopt a concentric approach that requires targeted research, information dissemination, infrastructure development, and agricultural technical institution establishments to boost income diversification and livelihood
Farmers’ preferences for sustainable intensification attributes in sorghum-based cropping systems: evidence from Mali
Get PDFSorghum plays a crucial role in the rural economy and nutrition of rural households in Mali. Yet the productivity of this crop is constrained by limited adoption of agricultural intensification technologies, which could be partly because technology development does not properly
consider farmers’ preferences. This study with smallholder farmers in southern Mali aimed to assess farmers’ preferences for different attributes of sorghum technologies through the lens of sustainable intensification. The study used a discrete choice experiment, a method which involves asking individuals to state their preference over hypothetical alternative scenarios, goods or services. We considered six attributes corresponding to different domains of sustainable intensification: grain yield, risk of yield loss, soil fertility, nutrition, labor requirement and
fodder yield. We analyzed the data using the mixed logit model, while considering the multinomial logit model as a robustness check. The findings revealed that smallholder farmers are strongly interested in transitioning from their existing sorghum-based cropping systems to those that closely align with these domains of sustainable intensification. However, there were diverse preferences among all the smallholder farmers studied, and between distinct sub-groups of smallholder farmers characterized by their social networks and agroecological zones, which yield relevant policy implications. Overall, these results support the growing research and development prioritization and policy interests toward scaling sustainable intensification among farmers, with a particular focus on human nutrition
Climate-smart agricultural practices influence the fungal communities and soil properties under major agri-food systems
Get PDFFungal communities in agricultural soils are assumed to be affected by climate, weather, and anthropogenic activities, and magnitude of their effect depends on the agricultural activities. Therefore, a study was conducted to investigate the impact of the portfolio of management practices on fungal communities and soil physical–chemical properties. The study comprised different climate-smart agriculture (CSA)-based management scenarios (Sc) established on the principles of conservation agriculture (CA), namely, ScI is conventional tillage-based rice–wheat rotation, ScII is partial CA-based rice–wheat–mungbean, ScIII is partial CSA-based rice–wheat–mungbean, ScIV is partial CSA-based maize–wheat–mungbean, and ScV and ScVI are CSA-based scenarios and similar to ScIII and ScIV, respectively, except for fertigation method. All the scenarios were flood irrigated except the ScV and ScVI where water and nitrogen were given through subsurface drip irrigation. Soils of these scenarios were collected from 0 to 15 cm depth and analyzed by Illumina paired-end sequencing of Internal Transcribed Spacer regions (ITS1 and ITS2) for the study of fungal community composition. Analysis of 5 million processed sequences showed a higher Shannon diversity index of 1.47 times and a Simpson index of 1.12 times in maize-based CSA scenarios (ScIV and ScVI) compared with rice-based CSA scenarios (ScIII and ScV). Seven phyla were present in all the scenarios, where Ascomycota was the most abundant phyla and it was followed by Basidiomycota and Zygomycota. Ascomycota was found more abundant in rice-based CSA scenarios as compared to maize-based CSA scenarios. Soil organic carbon and nitrogen were found to be 1.62 and 1.25 times higher in CSA scenarios compared with other scenarios. Bulk density was found highest in farmers' practice (Sc1); however, mean weight diameter and water-stable aggregates were found lowest in ScI. Soil physical, chemical, and biological properties were found better under CSA-based practices, which also increased the wheat grain yield by 12.5% and system yield by 18.8%. These results indicate that bundling/layering of smart agricultural practices over farmers' practices has tremendous effects on soil properties, and hence play an important role in sustaining soil quality/health
Leaf anatomy as an aid to the taxonomy of the ‘babassu’ complex (Attalea species)
No full textThe taxonomy of Attalea is still not mutually agreed upon by taxonomists. Since leaf anatomy is a useful tool to differentiate palm groups that are difficult to distinguish, this study aimed to check the taxonomic value of leaf anatomy of seven Attalea species, and estimate the genetic distance among the studied species. Samples were gathered in the Brazilian states of Maranhão, Tocantins, Bahia and Minas Gerais, and permanent slides were assembled following the classical plant anatomy protocol. All species presented uniseriate epidermis, glandular scars, tetracytic stomatal complex, expansion tissue with three cell layers and dorsiventral mesophyll. Attalea barreirensis was the only amphistomatic species, due to the constant fluctuation in soil moisture. The hypodermis was thinner in A. maripa, which is consistent with the humid habitats where the species occurs. In A. barreirensis and A. eichleri the distinction between palisade and spongy parenchyma was not so clearly seen, characterizing a gradual dorsiventral mesophyll. The distinct shapes of the margin and the main vascular bundle of the segments, as well as the number of palisade parenchyma layers, were important diagnostic features. The arrangement of vascular bundles and their connection with the hypodermis varied within the same species. Attalea barreirensis, A. eichleri and A. vitrivir had many anatomical features in common, which separated them from the remaining studied species. Leaf anatomy of the seven species was informative, and an anatomical identification key is provided